QuakeIndex

Earthquake · automatic estimate, may change

M 2.1md

12 km NNE of Bay Point, CA

· 2.3 km deep · released about 43 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Solano County 15 kmContra Costa County 24 kmNapa County 54 kmAlameda County 54 kmYolo County 60 kmSan Joaquin County 62 kmSacramento County 62 kmMarin County 72 kmSan Mateo County 89 km
Distance rings around the epicentre, with the nearest towns at their true direction and later quakes as coloured dots. Not a shaking map — see the USGS ShakeMap for that.
When
Magnitude
M 2.1 (md)
Depth
2.3 km below the surface
Felt
no reports yet
Nearest
Solano County, 15 km N
Status
Automatic — a machine’s first estimate, which may change

USGS · last changed by USGS · we first saw it 561 days ago

This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.

How big was it?

This earthquake released about 43 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.1 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 350,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 250,000× the energy of this one
  3. Around the size people start to feel M 3.0 22× the energy of this one
  4. This earthquake M 2.1 about 43 lb of TNT

Energy from the Gutenberg–Richter relation (log10E = 1.5M + 4.8), rounded to two figures; bar length is magnitude, which is already a logarithm of energy. Magnitudes of past earthquakes from the USGS catalogue.

Where

Epicentre 38.1365, -121.9317. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Solano County, CA 15 km (9 mi) S of here earthquakes near Solano County
Contra Costa County, CA 24 km (15 mi) N of here earthquakes near Contra Costa County
Napa County, CA 54 km (33 mi) SE of here earthquakes near Napa County
Alameda County, CA 54 km (34 mi) N of here earthquakes near Alameda County
Yolo County, CA 60 km (38 mi) S of here earthquakes near Yolo County
San Joaquin County, CA 62 km (38 mi) WNW of here earthquakes near San Joaquin County

Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.

Aftershocks so far

57 earthquakes have been recorded within 50 km since this one.

  1. 1.7 11 km NNE of Bay Point, CA
  2. 2.9 6 km SW of Alamo, CA
  3. 2.2 6 km SW of Alamo, CA
  4. 2.3 3 km W of Orinda, CA
  5. 1.6 5 km SW of Alamo, CA
  6. 1.6 16 km ENE of Yountville, CA
  7. 2.1 5 km ENE of Vallejo, CA
  8. 1.7 5 km NNW of Orinda, CA
  9. 1.6 2 km SW of Clayton, CA
  10. 1.5 16 km NE of Yountville, CA
  11. 1.7 5 km E of Vallejo, CA
  12. 2.1 1 km NNW of San Pablo, CA
  13. 2.4 1 km NNW of San Pablo, CA
  14. 1.5 1 km of San Pablo, CA
  15. 1.6 8 km NNE of Livermore, CA

Counted from the QuakeIndex database, which ingests the USGS feed every 30 seconds · as of . QuakeIndex does not forecast aftershocks. When USGS issues an operational aftershock forecast it appears on the USGS event page.

For this area

The largest earthquake within 50 km in our catalogue was M 4.5 on 2019-10-15 — it released about 3,500 times the energy of this one.

From the QuakeIndex catalogue, built from the USGS FDSN event service.

On USGS

QuakeIndex does not issue warnings. For earthquake early warning see ShakeAlert.